DNA-FINGERPRINTING DETECTS GENETIC-VARIABILITY IN THE PEARL-MILLET DOWNY MILDEW PATHOGEN (SCLEROSPORA-GRAMINICOLA)

Genetic variability in six host genotype-specific pathotypes of pearl millet downy mildew pathogen S. graminicola was studied at the molecul ar level using mini- and micro-satellites. Our results indicated that microsatellites (GAA)(6), (GACA)(4), and especially (GATA)(4) were qui te informative and showed high levels of polymorphism among the pathot ypes. The six pathotypes could be classified into five groups based on the cluster analysis of their genetic similarities, thereby confirmin g the existence of distinct host genotype-specific virulence in S. gra minicola pathotypes. We demonstrate, for the first time, the use of DN A fingerprinting to detect genetic variation in downy mildew fungus of pearl millet.